The present invention relates generally to an envelope structure for securely sending credit cards, debit cards and other sensitive material through the mail. In particular the present invention relates to an envelope structure which includes tamper evident indicators for determining whether or not the mailing has been tampered with.
Various designs have been proposed in the past for making envelopes tamper evident. Typical of these designs is the construction shown in U.S. Pat. No. 4,566,627, owned by the present assignee herein. It is also possible to provide tamper evidence in an envelope construction with the use of special adhesives that bond closure flaps in such a way that the closure flaps cannot be opened without producing fiber tear. However, even when such adhesives are used, it is also desirable to incorporate into the envelope additional tamper evident features to maintain the security of the enclosed materials. It is an object of the present invention to satisfy these and other needs with the use of unique opening features that also serve as tamper evident indicators.